package com.ts.framework.utils;

import java.text.SimpleDateFormat;
import java.util.Date;

/**
 * Created by mrt on 2020/3/27.
 */
public class GenerateOrderNum {
      /**
       * 锁对象，可以为任意对象
       */
      private static Object lockObj = "lockerOrder";
      /**
       * 订单号生成计数器
       */
      private static long orderNumCount = 0L;
      /**
       * 每毫秒生成订单号数量最大值
       */
      private int maxPerMSECSize=1000;

      /**
       *
       */

      /**
       * 生成非重复订单号，理论上限1毫秒1000个，可扩展
       * @param tname 测试用
       */
      public synchronized void generate(String tname) {
            try {
                  // 最终生成的订单号
                  String finOrderNum = "";
                  synchronized (lockObj) {
                        // 取系统当前时间作为订单号变量前半部分，精确到毫秒
                        long nowLong = Long.parseLong(new SimpleDateFormat("yyyyMMddHHmmssSSS").format(new Date()));
                        // 计数器到最大值归零，可扩展更大，目前1毫秒处理峰值1000个，1秒100万
                        if (orderNumCount >= maxPerMSECSize) {
                              orderNumCount = 0L;
                        }
                        //组装订单号
                        String countStr=maxPerMSECSize +orderNumCount+"";
                        finOrderNum=nowLong+countStr.substring(1);
                        orderNumCount++;
                        System.out.println(finOrderNum + "--" + Thread.currentThread().getName() + "::" + tname );
                        // Thread.sleep(1000);
                  }
            } catch (Exception e) {
                  e.printStackTrace();
            }
      }

      public static void main(String[] args) {
            // 测试多线程调用订单号生成工具
            /*try {
                  for (int i = 0; i < 200; i++) {
                        Thread t1 = new Thread(new Runnable() {
                              public void run() {
                                    GenerateOrderNum generateOrderNum = new GenerateOrderNum();
                                    generateOrderNum.generate("a");
                              }
                        }, "at" + i);
                        t1.start();

                        Thread t2 = new Thread(new Runnable() {
                              public void run() {
                                    GenerateOrderNum generateOrderNum = new GenerateOrderNum();
                                    generateOrderNum.generate("b");
                              }
                        }, "bt" + i);
                        t2.start();
                  }
            } catch (Exception e) {
                  e.printStackTrace();
            }*/
            System.out.println(System.currentTimeMillis());
      }
}
